EP 0335493 A2 19891004 - Oscillator.
Title (en)
Oscillator.
Title (de)
Oszillator.
Title (fr)
Oscillateur.
Publication
Application
Priority
JP 4566688 A 19880227
Abstract (en)
The collectors of first and second transistors (5, 6) of a differential amplifier circuit are connected to one terminal of a DC power source (1) respectively through first and second resistors (8, 9). The emitters of the first and second transistors (5, 6) are connected to the other terminal of the DC power source (1) through a common current-source (7), and the bases of the first and second transistors (5, 6) are connected to a bias circuit (10) for applying a bias voltage. At least one port (3) of a piezo-electric device (2) having at least two ports on a single substrate is connected between the collectors of the first and second transistors (5, 6), and the remaining port (4) is connected between the bases of the first and second transistors (5, 6). The transistors (5, 6) can be field effect transistors, and the common current-source can be a resistor (15). In this oscillator, since no DC voltage is applied across transducers of each port, degradation of a piezo-electric device can be prevented. The circuit has a complete symmetrical arrangement, and only a DC current flows in from the power source (1). For this reason, the circuit does not serve as a noise source for another circuit connected to the power source, and is not easily influenced by noise from the other circuit. Since no large-capacitance capacitor is required, the oscillator is suitable for an integrated circuit.
IPC 1-7
IPC 8 full level
H03B 5/32 (2006.01)
CPC (source: EP KR US)
H03B 5/326 (2013.01 - EP US); H03B 5/36 (2013.01 - KR)
Designated contracting state (EPC)
DE FR GB
DOCDB simple family (publication)
EP 0335493 A2 19891004; EP 0335493 A3 19900905; EP 0335493 B1 19951129; DE 68924922 D1 19960111; DE 68924922 T2 19960605; KR 890013873 A 19890926; KR 920009457 B1 19921016; US 4897621 A 19900130
DOCDB simple family (application)
EP 89301631 A 19890220; DE 68924922 T 19890220; KR 890002526 A 19890227; US 31255789 A 19890221